I have used them internationally for years and years and years.
MOST T-MOBILE CUSTOMERS ARE GETTING FASTER INTERNATIONAL INTERNET —
BUT THE UPGRADE FOR MAGENTA MAX CUSTOMERS
T-Mobile says that Magenta Max customers (and Business Unlimited
Ultimate customers) will get 5GB of high-speed data each month in over
210 countries. Previously, Magenta Max subscribers could expect speeds
around 256kbps in most countries. Now, they’ll get “the highest speed
data available, including 5G,” according to T-Mobile’s announcement
video. Obviously, this is describing the best-case scenario; your
speeds will depend on the coverage wherever you’re visiting.
Regular Magenta customers are getting that same deal, but it’s limited
to 11 European countries: Austria, Croatia, Czech Republic, Germany,
Greece, Hungary, Macedonia, Montenegro, Poland, Romania, and Slovakia.
In the approximately 199 other countries, Magenta customers and most
other T-Mobile subscribers can expect to get around 256kbps speeds.
That is, however, an upgrade. Before now, non-Max customers were
getting around half that when traveling internationally.